Methods and systems for static multimode multiplex spectroscopy

Abstract

Methods and systems for static multimode multiplex spectroscopy are disclosed. According to a method for static multimode multiplex spectroscopy, spectral energy emanating from different points of a diffuse source is simultaneously received. Different multi-peak filter functions are applied to the spectral energy emanating from the different points to produce a multi-channel spectral measurement for each point. The multi-channel spectral measurements are combined to estimate a property of the diffuse source.

1. A method for static multimode spectroscopy, the method comprising:
 (a) simultaneously receiving spectral energy emanating from a plurality of different spatial points of a diffuse source; 
 (b) applying different multi-peak filter functions to the spectral energy emanating from the different points using an optical component to produce a multi-channel spectral measurement for each point, wherein the multi-channel spectral measurement is converted to an electrical signal by an element of a detector array and wherein the optical component is located between the diffuse source and the detector array; and 
 (c) combining the multi-channel spectral measurements for the different points to estimate a property of the diffuse source, wherein combining the multi-channel spectral measurements to estimate a property of the source includes combining the multi-channel spectral measurements to estimate an average spectrum of the source and wherein combining the multi-channel spectral measurements to estimate an average spectrum of the source includes inverting the filter functions and integrating over an area of the source. 
 
   
   
     2. The method of  claim 1  wherein simultaneously receiving spectral energy emanating from the plurality of different spatial points of the diffuse source includes receiving spectral energy emanating from a plurality of different spatial points of a biological sample. 
   
   
     3. The method of  claim 2  wherein simultaneously receiving spectral energy emanating from the plurality of different points of the biological sample includes receiving spectral energy emanating from a plurality of different points of a tissue sample. 
   
   
     4. The method of  claim 1  wherein simultaneously receiving spectral energy emanating from the plurality of different points of the diffuse source includes simultaneously receiving spectral energy emanating from a plurality of different points of a diffuse gas. 
   
   
     5. The method of  claim 1  wherein applying different multi-peak filter functions to the spectral energy emanating from the different points using the optical component comprises passing the spectral energy from each point through a two-beam interferometer having a different interference path length for the spectral energy emanating from each point. 
   
   
     6. The method of  claim 1  wherein applying different multi-peak filter functions to the spectral energy emanating from the different points using the optical component to produce a multi-channel spectral measurement for each point comprises passing the spectral energy from each point through a filter, wherein each filter has a different multi-peak response function. 
   
   
     7. The method of  claim 6  wherein passing the spectral energy emanating from each point through the filter includes passing spectral energy emanating from each point through a thin film filter. 
   
   
     8. The method of  claim 6  wherein passing the spectral energy emanating from each point through the filter includes passing spectral energy emanating from each point through a volume hologram. 
   
   
     9. The method of  claim 6  wherein passing the spectral energy emanating from each point through the filter includes passing spectral energy emanating from each point through an array of photonic crystals. 
   
   
     10. The method of  claim 1  wherein combining the multi-channel measurements to estimate a property of the source includes combining the multi-channel measurements to estimate density of chemical compounds in the source. 
   
   
     11. A method for static multimode spectroscopy, the method comprising:
 (a) simultaneously receiving spectral energy emanating from a plurality of different spatial points of a diffuse source; 
 (b) applying different multi-peak filter functions to the spectral energy emanating from the different points to produce a multi-channel measurement for each point by sampling the spectral energy emanating from the different points using a detector array comprising a plurality of quantum dots; and 
 (c) combining the multi-channel spectral measurements for the different points to estimate a property of the diffuse source, wherein combining the multi-channel spectral measurements to estimate a property of the source includes combining the multi-channel spectral measurements to estimate an average spectrum of the source and wherein combining the multi-channel spectral measurements to estimate an average spectrum of the source includes inverting the filter functions and integrating over an area of the source. 
 
   
   
     12. A method for estimating a spatially averaged spectral density of a diffuse source of optical radiation, comprising:
 integrating spectral energy of different modes of the diffuse source against a diversity of multi-peak spectral multiplexing functions at a same instance in time using an array of spatially distributed optical components and an optical detector array, wherein the array of spatially distributed optical components is located between the diffuse source and the optical detector array and wherein the optical detector produces an array of measurements; and 
 mathematically inverting the array of measurements to estimate the spatially averaged spectral density using a computer. 
 
   
   
     13. The method of  claim 12 , wherein mathematically inverting the array of measurements to estimate the spatially averaged spectral density comprises multiplying the array of spectral energy measurements by an inverted array of the multi-peak spectral multiplexing functions. 
   
   
     14. A method for estimating a target component density of chemical or biological spectral materials in a diffuse source of optical radiation, comprising:
 integrating spectral energy of different modes of the diffuse source against a diversity of multi-peak spectral multiplexing functions at a same instance in time using an array of spatially distributed optical components and an optical detector array, wherein the array of spatially distributed optical components is located between the diffuse source and the optical detector array and wherein the optical detector produces an array of measurements; and 
 computationally analyzing the array of measurements to estimate the target component density using a computer, wherein computationally analyzing the array of measurements to estimate the target component density comprises linearly inverting a transformation between the target component density and the array of measurements. 
 
   
   
     15. A method for static multimode spectroscopy, the method comprising:
 (a) simultaneously receiving spectral energy emanating from a plurality of different spatial points of a diffuse source; 
 (b) applying different multi-peak filter functions to the spectral energy emanating from the different points using an optical component to produce a multi-channel spectral measurement for each point, wherein the multi-channel spectral measurement is converted to an electrical signal by an element of a detector array and wherein the optical component is located between the diffuse source and the detector array; and 
 (c) combining the multi-channel spectral measurements for the different points to estimate a property of the diffuse source, wherein combining the multi-channel spectral measurements to estimate a property of the source includes combining the multi-channel spectral measurements to estimate an average spectrum of the source and wherein combining the multi-channel spectral measurements to estimate an average spectrum of the source includes combining the spectral measurements for the different modes using the cross spectral density. 
 
   
   
     16. A method for static multimode spectroscopy, the method comprising:
 (a) simultaneously receiving spectral energy emanating from a plurality of different spatial points of a diffuse source; 
 (b) applying different multi-peak filter functions to the spectral energy emanating from the different points using an optical component to produce a multi-channel spectral measurement for each point, wherein the multi-channel spectral measurement is converted to an electrical signal by an element of a detector array and wherein the optical component is located between the diffuse source and the detector array; and 
 (c) combining the multi-channel spectral measurements for the different points to estimate a property of the diffuse source, wherein applying different multi-peak filter functions to the spectral energy emanating from the different points using an optical component to produce a multi-channel spectral measurement for each point comprises passing the spectral energy from each point through an optical fiber and a fiber interferometer, wherein the fiber interferometer for each point has a different interferometric response. 
 
   
   
     17. A system for static multimode multiplex spectroscopy, the system comprising:
 (a) an illumination source for illuminating an object of interest; 
 (b) an interferometer array for simultaneously receiving spectral energy emanating from a plurality of different points on the object of interest and for applying different multi-peak filter functions to the spectral energy emanating from the different points; 
 (c) a detector array optically coupled to the interferometer array for receiving the filtered spectral energy and for converting the spectral energy into electrical signals; and 
 (d) a multi-peak spectral measurements combination module for receiving the electrical signals from the detector array and for combining the electrical signals to estimate a property of the object, wherein the interferometer array comprises a plurality of fiber interferometers having different multi-peak interferometric responses.